I don't understand how to add negative fraction with a positive

The addition of negative fraction to a positve fraaction is simply subtraction of fractions with sign of result depend upon the sign of larger fraction.
Simplify the fraction.
[tex]\begin{gathered} -\frac{4}{5}+\frac{6}{5}=\frac{6}{5}-\frac{4}{5} \\ =\frac{6-4}{5} \\ =\frac{2}{5} \end{gathered}[/tex]Answer is 2/5.